Steller's Sea-Cow (Hydrodamalis gigas/Rhytina gigas), extinct aquatic mammal. Artist's realisation of the giant sea-cow discovered by Georg Wilhelm Steller 1709-1746) Russian ornithologist on the Danish navigator Vitus Bering's (Behring) second Kamchatka expedition, 1741. From 'Extinct Monsters' by the Rev. HN Hutchinson (London, 1893).